Quality is not a given; it is a earned.
质量不是给定的；它是赢得的。
多项式时间归约的概念对于理解NP完全问题的结构至关重要。
It is common sense to take a method and try it. If it fails, admit it frankly and try another. But above all, try something.
我和普通人一样。会受伤也会流血，也很容易难为情。
我最大的对手就是我自己。